function up= toUpper(cha)
% up is the upper case letter corresponding to lower case letter cha.
% If cha is not a lower case letter, do not capitalize and up is simply cha.

up= cha;

if ( cha >= 'a' && cha <= 'z' )
    distance= cha - 'a';  % how far cha is from 'a'
    up= char('A' + distance);
end